This year, we published on the following topics related to MMR. (1) We provided evidence that MMR corrects replication errors made by Pol alpha more efficiently than it repairs replication errors made by Pol delta. These data have several implications for the mechanism of MMR in vivo. (2) We collaborated to provide evidence that malaria drug resistance is associated with defective DNA mismatch repair. (3) We supported a study to understand how yeast PMS1, a MMR protein with an essential endonuclease activity, binds to DNA. (4) We participated in four different studies that exclude participation of MMR in (a) genome instability resulting from unrepaired ribonucleotides in DNA, (b) correcting mismatches generated in mutator yeast strains lacking two non-essential accessory subunits of Pol epsilon, (c) FAN1-dependent repair of interstrand crosslinks, or (d) a newly discovered role of cyclin D1 in DNA repair.